FBI agents are not paid in hourly wages, they are paid through the federal government system GS ratings which provides agents an annual salary rating for years served.
The tariff of the United States, like all actual protective tariffs, is partly revenue and partly protective, its original purpose of yielding revenue having been subordinated to that of giving protection, until it may now be best described as a protective tariff yielding incidental revenue.
A tariff is a tax that is placed on an imported good. A tariff is a tax on an imported good. Therefore for each unit of a good that is imported into a country the tariff increases the price of that good by however much the tariff is. Tariffs are usually implemented when the world price of a good is lower than the domestic price of a good.